Clamping device



June 22, 1965 R. s. HARTWELL 3,139,952

cmmrme DEVICE Filed Nov. 7. 1962 2 Sheets-Sheet L June 1965 k. e. HARTWELL 89, 2

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Filed Nov. 7, 1962 United States Patent 3,189,962 CLAMPING DEVICE Ronald G. Hartwell, Hummelstown, Pa., assiguor to AMP Incorporated, Harrisburg, Pa. Filed Nov. 7, 1962, Ser. No. 236,000 3 Claims. (Cl. 24-126) This invention relates to adjustable clamping devices for clamping objects having a generally circular cross section such as electrical cables.

An object of the invention is to provide an improved clamping device for electrical cables. A further object is to provide an adjustable clamping device which maintains substantially complete circumferential engagement with the object being clamped regardless of the diameter of the object. A still further object is the provision of an adjustable cable clamp having a small number of component parts.

These and other objects of the invention are achieved in one preferred embodiment comprising a generally cylindrical clamping ring which is made up of a plurality of identical interfitting unit parts. Each unit of the clamping ring has an axial section or rib, which constitutes an element of the cylinder, with offset fingers extending transversely from its opposite sides. These fingers extend generally arcuately from the axial element and are spaced apart by a distance substantially equal to their width so that a plurality of these elements can be arranged about a common axis with their fingers interdigitated to form a continuous enclosure about the object being clamped. The preferred embodiment includes a housing for the cylindrical clamp and means for moving the individual elements radially inwardly towards the common axis referred to above thereby to decrease the circumference of the clamp and to adapt it to the clamping of objects of varying sizes.

In the drawing:

FIGURE 1 is an exploded perspective view of a preferred form of clamping device in accordance with the invention.

FIGURE 2 is a perspective view, with parts broken away, of the preferred embodiment showing the parts assembled.

FIGURE 3 is a perspective exploded view of a set of the individual units which comprise the clamping ring.

FIGURE 4 is a side View with parts broken away showing the preferred embodiment of clamping device in assembled relationship with a multi-contact connector.

FIGURES 5 and 6 are fragmentary sectional views showing the manner in which a cable is clamped, the clamping member 26 being shown as a solid cross section in these views in the interest of simplicity.

The disclosed embodiment of the invention comprises a housing 2 having a suitable mounting flange 4 thereon by means of which it may be secured to the hood or housing of an electrical connector 5, the disclosed embodiment having shoulder means which interfits with complementary shoulder surfaces on the connector housing as shown at 7. The disclosed connector 5 is of the type described in U.S. Patent 3,034,089 although the invention is obviously usable with other types of multi-contact connecting devices. A generally diamond or oval shaped recess 6 extends inwardly of the housing 2 from the upper side thereof as viewed in FIGURE 2 up to a rear wall section 8. A centrally located circular opening 10 is provided in this rear wall section 8 and a conical camming surface 12 extends divergently inwardly from this opening. Openings 14 for adjusting screws 15 are provided on diametrically opposite sides of the circular opening 10 and open into the oval recess 6 at its apices.

Patented June 22, 1965 j The screws-15 which extend through these openings are received in threaded openings in cars 18 on opposite sides of a camming ring 16 having a central circular opening 17 of the same size as the opening 10. The camming ring has a conical camming surface 24 on its underside as viewed in the drawing which is identical to the camming surface 12 and which faces in the opposite direction to the camming surface 12. It will be apparent that upon threading the screws 15 into and through the openings in the camming ring, the camming ring will be pulled from the position of FIGURE 5 to the position of FIGURE 6 thereby to bring the two camming surfaces 12, 24 relatively towards each other.

The cable is clamped by means of a generally cylindrical clamping member 26 which is composedof a plurality of identical parts 28. Each of these identical parts of the clamping member has an axial element 30 which constitutes an axial element of the cylinder 26 and has fingers 3-2, 34 extending from one side thereof and fingers 36, 38 extending from the opposite side. The fingers 32, 34 are axially offset relative to the fingers 36, 38 and the spacing between the pairs of fingers is substantially equal to or slightly greater than the thickness of the fingers. The inner surfaces of these fingers are generally arcuate and merge with the arcuate inner surface of the axial element 30 so that when a plurality of parts are fitted together with the fingers of adjacent sections being interdigitated, a generally cylindrical internal surface is formed.

The external surf-ace of the finger 32, and the external surface of the finger 38, is of conical form as shown at 39 and 41 and slopes towards the axis of the cylinder at an angle of about 45 degrees corresponding to the angles of the camming surfaces 12, 24. T hus,an assembled clamping member comprising a plurality of identical clam-pingparts will present at its opposite ends, a surface compatible with, and adapted to bear against, the.

camming surfaces 12, 24. It is preferable to provide a slight bevel as shown at 33 and 35 on the fingers 34 and 36 so as to provide maximum bearing surface between the clamping ring and the surfaces 12, 24. It is also advantageous to provide a slight chamfer on the ends of the fingers 34 and 36 as indicated at 42 and 44 in order to facilitate movement of the individual elements towards each other during adjustment as described below. i

In use, the cable C is threaded through the opening 10, through the clamping cylinder composed of the individual clamping elements, and through the opening in the camming ring. It is understood that the individual wires on the cable will extend to electrical contact terminals mounted in the housing of the connector assembly. When it is desired to clamp the cable, it is merely necessary to tighten the screws 15 thereby to cause movement of the camming surfaces 12, 24 towards each other with concomitant radial inward movement of the individual parts of the clamp until the cable is firmly clamped around its entire periphery. The internal configuration of the clamping member itself will remain substantially circular regardless of its position of adjustment so that the cable and the individual conductors therein will be uniformly stressed around the cable periphery.

It will be apparent that the clamping member 26 is, in effect, made up of four co-axial side-by-side rings, each ring in turn comprising a plurality of segments which are circumferentially spaced apart. Thus in FIGURE 1, the uppermost ring is composed of the four fingers 32 which constitute its segments and the adjacent ring is composed of the four fingers 36 which constitute the segments of this adjacent ring, the segments 32 being circumferentially offset, relative to the axis of member 26, with respect to the segments 36. When the diameter J) of clamping member 26 is reduced, these segments move toward its axis.

Changes in construction will occur to those skilled in the ant and various apparently different modifications and embodiments may be made without deputing from the scope of the invention. The matter set forth in the foregoing description and accompanying drawings is ofiered by way of illustration only. The actual scope of the invention is intended to be defined in the following claims when viewed in their proper perspective against the prior art.

I claim:

1. A clamping device for clamping an object having a generally circular cross-section, said device comprising a plurality of interfittting elements, each of said elements comprising an axial element of a cylinder having an even number of arcuate fingers extending laterally from its sides, the fingers on one side of said element being offset along the length of said element from the fingers of the other side and the fingers on each side being spaced apart by a distance equal to the thickness of said fingers, the end finger on each side having a segmental conical camming surface, said elements being arranged around a common axis with the fingers of each part being interdigitated with the fingers of adjacent parts, said segmental conical surfaces forming a camming surface at each end of said clamping means whereby, upon movement of com-' plementary conical camming surfaces against said conical surfaces, said parts are moved relatively inwardly towards said common axis to reduce the inside diameter of said clamping means.

2. A cable clamping device comprising, a housing, an opening in said housing through which said cable is adapted to be passed, a pair of conical camming surfaces in said housing, said conical surfaces being coaxially disposed with respect to said opening, means for adjusting said surfaces relatively toward and away from each other, a plurality of identical interfitting pants in said housing and between said camming surfaces, each of said parts comprising an axial element of a cylinder having an even number of arcuate fingers extending laterally from its sides, the fingers on one side of each element being offset along the length of said element from the fingers on the other side and the fingers on each side being spaced apart by a distance equal to the thickness of said fingers, the fingers on the ends of said element extending in opposite lateral directions and each having a segmental conical camming surface, said parts being arranged around parallel to said axis and with the fingers of each part being interdigitated with the fingers of'the next adjacent part, said camming surfaces of said fingers being disposed against said pair of camming surfaces in said housing whereby, upon adjustment of said camming surfaces in said housing towards or away from each other, said elements are moved towards and away from the axis of said opening to vary the inside diameter of said clamping means and to permit clamping of cables of varying sizes.

3. A cable clamping device comprising, a housing, an opening in said housing through which said cable is adapted to be passed, a first conical camming surface in said housing surrounding said opening, a camming ring in said housing in axial alignment with said opening, said camming ring having a second conical camming surface in opposed relationship to said first conical camming surface, a plurality of identical interfitting parts in said housing and between said camming surfaces, each of said pants comprising an axial element of a cylinder having an even number of arcuate fingers extending laterally form its sides, the fingers on one side of each element being offset along the length of said element from the fingers on the other side and the fingers on each side being spaced apart by a distance equal to the thickness of said fingers, the fingers on the ends of said element extending in opposite lateral directions and each having a segmental conical camming surface, said parts being arranged around the axis of said opening with said elements extending parallel to said axis and with the fingers of each part being interthe axis of said opening with said elements extending References Cited by the Examiner UNITED STATES PATENTS 1,853,681 4/32 Hayes 24-123 2,263,364 11/41 Nichols.

2,823,248 2/58 Schaefer 24-126 X 3,034,089 5/62 Curtis 7 339-49 3,072,988 1/63 Pennington 24-126 DONLEY J. STOCKING, Primary Examiner. 

1. A CLAMPING DEVICE FOR CLAMPING AN OBJECT HAVING A GENERALLY CIRCULAR CROSS-SECTION, SAID DEVICE COMPRISING A PLURALITY OF INTERFITTING ELEMENTS, EACH OF SAID ELEMENTS COMPRISING AN AXIAL ELEMENT OF A CYLINDER HAVING AN EVEN NUMBER OF ARCUATE FINGERS EXTENDING LATERALLY FROM ITS SIDES, THE FINGERS ON ONE SIDE OF SAID ELEMENT BEING OFFSET ALONG THE LENGTH OF SAID ELEMENT FROM THE FINGERS OF THE OTHER SIDE AND THE FINGERS ON EACH SIDE BEING SPACED APART BY A DISTANCE EQUAL TO THE THICKNESS ON SAID FINGERS, THE END FINGER ON EACH SIDE HAVING A SEGMENTAL CONICAL CAMMING SURFACE, SAID ELEMENTS BEING ARRANGED AROUND A COMMON AXIS WITH THE FINGERS OF EACH PART BEING INTERDIGITATED WITH THE FINGERS OF ADJACENT PARTS, SAID SEGMENTAL CONICAL SURFACES FORMING A CAMMING SURFACE AT EACH END OF SAID CLAMPING MEANS WHEREBY, UPON MOVEMENT OF COMPLEMENTARY CONICAL CAMMING SURFACES AGAINST SAID CONICAL SURFACES, SAID PARTS ARE MOVED RELATIVELY INWARDLY TOWARDS SAID COMMON AXIS TO REDUCE THE INSIDE DIAMETER OF SAID CLAMPING MEANS. 